Add stability condition table

Created by: Zaharid

Add a table to compute the stability of dataset covariance matrices.

There are a few things I am not convinced about, namely some amount of code duplication, the fact that I am not sure which exact covmat provider to use as input or that this should really be working with square root matrices in the first place. It however solved the immediate problem of having this in master.

Closes #1262 (closed).